Recently, due to consumer demand for immersive sensations and technology innovation of displays, huge wall-sized TVs (about 70-120 inches), so-called UDTV (Ultra Definition TV), have drawn much attention in the industry. Typically, the UDTV has a relatively ultra-high resolution which is, e.g., 3840 pixels×2160 lines (4K-UDTV) or 7680 pixels×4320 lines (8K-UDTV), and requires a huge amount of bandwidth to transmit UDTV video through a communication medium (wired/wireless) or broadcasting line. Such a large bandwidth or a large block of data for coding the UDTV video may increase the likelihood of motion mismatch, resulting in creating an excessive amount of coded data, while increasing the efficiency of spatial and temporal coding of the UDTV video. Thus, there is an interest in developing adaptive coding schemes having an optimized variable block size for coding the UDTV video.